1. Technical Field
The present disclosure relates to a method for manufacturing a printed circuit board (PCB), and more particularly, a method for smoothing a PCB.
2. Description of Related Art
In a traditional buried hole metallization process of manufacturing a multilayer PCB, the buried hole is filled with an electrically conductive material to electrically connect two adjacent conductive layers (e.g. copper layer) on two opposite sides of a substrate. However, after filling the buried hole, the surface of the conductive layers may have dimples. The dimples may cause a series of problems in the continuing processes, such as electrically conductive traces formed from the electrically conductive layers using a typical exposing, developing and etching process have different line widths in different areas. Hence, it is necessary to provide a method for manufacturing PCBs can overcome above problems.